It is always true that the rate at which a solute dissolves can be increased by grinding. The smaller the solute the easier it will dissolve in the solvent, while other facts play into the rate at which a solute dissolves in a solvent, a major part of this is also how small the solute is. You can think of how rock salt is harder to dissolve in water compared to finely ground salt.
It is sometimes true that as the temperature of a solvent decreases, the solubility of a solute increase. The reason for this is that for liquids and solids as temperature increases the solubility increases but for gasses, as the temperature increases the solubility decreases.
It is always true that stirring a solute when adding it to a solvent should increase the rate of its dissolving. however, this will not increase the amount that is able to be dissolved in the solution.
It is never true that Henry's law states that the solubility of a gas in a liquid is a function of temperature. Henry's law is a gas law that was determined by William Henry in 1803. The law dictates that when in constant temperature the amount of gas that dissolves in a given volume of a liquid is proportional directly to the partial pressure of the gas at equilibrium with the desired liquid. In simpler terms, the solubility of the gas in a certain liquid is proportional to the partial pressure of the gas above the liquid.
It is always true that two liquids that dissolve in each other are miscible. Miscibility is described as the property of liquids and other substances to mix in all proportions and forming homogeneous solutions.
Answer:
Thermal energy typically flows from a warmer material to a cooler material.
Explanation:
Answer:
180.6 kJ
Explanation:
The enthalpy of reaction refers to the energy absorbed or released during a reaction. If heat is absorbed in a reaction, the enthalpy of reaction is positive. If heat is released in a reaction, the enthalpy of reaction his negative.
Since the energy absorbed when one mole of the intermediate is formed is 90.3 kJ/mol, then, when two moles of intermediate is formed, 2 × 90.3 kJ/mol = 180.6 kJ of energy is absorbed.
This is a trick question really, or at least the wording is poor chemistry. Molecules are the smallest unit of a simple covalent compound that retain the chemical properties of that compound. Covalent means there are bonds between atoms due to sharing a pair of electrons, and an example of such a compound is water, H2O. There are discrete H2O molecules moving past each other, with only weak intermolecular forces in between them.
Yet MgCl2 is not a covalent compound. In fact the bonding is ionic, meaning that electrons are transferred between the atoms to form positive and negative ions, which then electrostatically attract. Ionic compounds form a giant ionic lattice, a continuous structure of millions of these ions. An ionic molecule does not really exist.
What I assume is meant is the formula unit, a term very similar in meaning to a molecule. The difference is well shown by comparing empirical formula and molecular formula. A molecular formula shows how many of each atom are in a molecule, yet the empirical formula just shows the simplest whole-number ratio between the number of these atoms. Take ethane: the molecular formula is C2H6 and the empirical formula is CH3.
The ionic formula unit is like this empirical formula. By this standard the likely answer is A (1), because the formula shows that for every magnesium atom, there are two chlorine atoms.
I hope this helps :)
